Production of smoke signs in the air



Dec. 17, 1963 s. S. PIKE ETAL 3,

PRODUCTION OF SMOKE SIGNS IN THE AIR Filed June 24. 1960 2 Sheets-Sheet1 .23 2s 21 I 2 3 4 5 6 7 8 9 I0 ll [213M I5l6 l7l8 l9202l22 24 26 28--|5O I l =0 Z k 3 p0, Q 0 5 W 6 H 7 TRANSMITTER In? STOP START KEY KEYOSCILLATOR OSCILLATOR INVENTORS ROLF KROHN HANSEN NEY PIKE ATTORNEY Dec.17, 1963 s. s. PIKE ETAL PRODUCTION OF SMOKE SIGNS IN THE AIR 2Sheets-Sheet 2 Filed June 24, 1960 Q Q Q O Q Q o O 0 Q m l. o 0 0 Q 0 0o w mXw o o MES. nuroznm NN X\.

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INVENTORi ROLF KROHN HANSEN BY s. smmzy PIKE ATTQRNEY United StatesPatent.

3,114,214 PRQDUCTION OF SMOKE SIGNS IN THE AIR Sele Sidney Pike, HowardBeach, N.Y., and Rolf K.

Hansen, Wayne, N.J., assignors to Skywriting Corporaton of America, NewYork, N.Y., a corporation of New York Filed June 24, 1950, Ser. No.38,533 1 Claim. (Cl. 40-213) The present invention relates to a methodand apparatus for skywriting by a number of planes flying forwardly information, and the invention is an improvement with respect to themethod and apparatus set forth in our Patent No. 2,674,820, of April 13,1954.

The characteristic of the present invention is that each one of thegroup of planes receives a radio signal by a master or directional planeof the group, which signal automatically starts movement of a perforatedtape in each plane, the tape being driven by constant speed electricmotor. The tape actuates a solar or high current photoelectric cellwhich in turn operates a sensitive relay, the latter serving to actuatea heavy duty relay controlling a smoke valve, and such combination ofelements, briefly stated, is carried by each plane of the group. The newmethod and apparatus is an improvement with respect to our said PatentNo. 2,674,820, in that the mechanism for each plane which operates andcontrols the smoke pattern of that plane continues operating without theneed of any impulses except the initial starting pulse, and saidmechanism continues such operation without interference by outside radioimpulses.

A further utility of the present invention is that the perforatedendless tape is an operating member for the production of a plurality ofdifferent sky signs, to be selected at will by energizing theappropriate illuminating lamp by means of a selector switch.

The invention will be described with reference to the accompanyingdrawings in which:

FIG. 1 is a schematic view illustrating the formation by a plurality ofplanes according to the present invention.

FIG. 2 is a schematic view of the elements employed for transmitting thestarting radio impulse.

FIG. 3 is a schematic diagram showing the electronic apparatus in eachof the controlled planes.

FIG. 1 diagrammatically shows the manner in which a sign is formed inthe air. In that figure each letter is composed of suitably arrangedshort parallel lines of equal length, and the thickness of the heavystrokes in the letters may be approximately equal to the length of theseshort lines or a multiple thereof. The numbers to 150 in the first rowof this figure indicate time intervals during which smoke may or may notbe released. The numbers 1 to 7 in the first vertical row indicate theplane from which the smoke is emitted. It will be seen that any patterncomposed of blank and smoke spaces may thus be ascribed to all planes,the patterns for two different planes being, in general different.

In the particular embodiment shown, the word Buy is outlined. The firstplane will have to emit smoke for the time intervals 1, 2, 3, 4, 9, 10,11 and 17, no smoke being released at any other time, and the action ofeach of the remaining planes is correspondingly indicated.

The construction and operation of our embodiment shown in the drawingsis as follows:

Two audio oscillators 1, 2, operating at 11 kc. and kc. respectively areconnected through Key 1 (start) and Key 2 (stop) to the modulatingcircuit of a conventional radio transmitter 3, such as normally used inairplanes, and which is installed in the master or control plane. Theradio receiver 4 in each of the airplanes has two high pass filters 5,5,,, connected to the plate of the output ice circuit through suitablecoupling capacitors C1 and C2.

The 15 kilocycle filter 5 is connected through a diode to a sensitiverelay 6. When a 15 kc. signal of suflicient amplitude is received relay6 will close and latch. The contacts of relay 6 will place 12 volts DC.on magnetic clutch 7 and constant speed motor 8 will engage a tapeactuating sprocket 9 which moves the endless perforated tape 10. Anumber of illuminating lamps 11, 11,, enclosed in housings 12 eachhaving a small aperture are focussed on the various perforated tracks onthe tape. For purposes of illustration five tracks, or longitudinal rowsof perforations, are shown.

By selecting and energizing the proper lamp, light will shine on thetape in a very narrow area. A high output current photoelectric cell 14is placed directly underneath the light aperture, but with the tape inbetween. When the tape is pulled by the sprocket wheel, a sensitiverelay 15 will operate each time light hits the photocell through theperforations in the opaque tape. Relay 15 then energizes the coil ofrelay 16 which operates the smoke valve solenoid 17, permitting oil tobe injected into (and thence smoke out of) the exhaust pipe of theaircraft.

In order to stop the operation of the smoke control tape, the stop keyis operated and an 11 kc. signal is sent through the transmitter to thereceiver on through filter 5 energizing the coil of latch relay 18. Thisaction releases the latch 19 and the contacts of relay 6 return tonormal, thereby energizing clutch 20, engaging motor 21 which will turnthe tape back to start position. This is accomplished by using a secondphoto cell 22. It is placed under the tape in register with the fifthrow of perforations and lamp 11 is on at all times. When the startposition is reached, indicated by the fifth row per foration at 25,photo cell 22 energizes relay 23 which opens the circuit to clutch 20and closes the circuit to an indicator lamp 2 which indicates startingposition of the tape.

In case of a false start, the pilot in the lead plane pushes the stopkey and by the means above described the tape is returned to the startposition.

Having described our invention, what we claim and desire to secure byLetters Patent, is as follows:

Apparatus for controlling the flow of a visible trace forming substanceemitted by planes flying in formation, comprising a plurality of planes,a tape in each plane formed with perforations in accordance with desiredspaced ejections of a visible substance, a receiver on each plane forreceiving an audio impulse, an electrical circuit including saidreceiver, the receiver being adapted to close said circuit uponreceiving a specific audio impulse, a motor in said circuit, meansoperated by the motor for feeding longitudinally said tape, a dischargemember for such visible substance carried by the plane, a valve forcontrolling the discharge of such visible substance, electricallyoperated means for actuating said valve including an electric circuitleading to the perforated tape, closing and opening means for said lastnamed circuit and adapted to close the circuit as each perforationpasses into register therewith, and adapted to open the circuit betweensuccessive perforations in the tape, the said audio impulse receiverbeing adapted to open the said first circuit upon receiving apredetermined impulse, and an electrically operated clutch for saidmotor the tape in each plane being formed with a first row ofperforations common to all of the planes for the production of a givensign produced by all of the planes in coaction, and the tape beingformed with a second and additional rows of perforations, said secondrow of perforations in all of the planes being adapted, in co-action ofall of the planes, to produce a second sign different from the firstsign, and with the same operation with respect to each of the additionalrows of perforations for a distinct sign with reference to each row inall of the planes, a plurality of lamps, each for one row ofperforations in the tape, and for each plane, means for selectivelyenergizing said lamps, and a photocell for receiving light impulses froma selected lamp, said cell being in and adapted to close and open thecircuit leading to the means for actuating the valve.

UNITED STATES PATENTS Remey Mar. 28, Remey 'I Mar. 28, Badgley et a1.Dec. 25, Shaw Apr. 29, Hansen et al. Apr. 13, Angel et a1. Dec. 8,

